Satellite cells are a population of skeletal muscle stem cells that are located beneath the basal lamina surrounding the muscle fiber and are required for muscle growth and muscle repair after injury or exercise. Satellite cell number and function are affected by normal aging and in several diseases, resulting in progressive muscle wasting or inefficient recovery after injury. Examples include Duchenne muscular dystrophy, in which satellite cells are depleted through constant use, and sarcopenia, where satellite cells may both be depleted and adversely affected in their proliferative capacity by changes in their environment (Jejurikar and Kuzon, Apoptosis, 8 (2003), 573-578). Finding treatments that would expand the endogenous population of satellite cells could aid greatly in treating these debilitating diseases.
Thus, there is need in the art for compositions and methods for inducing satellite cell proliferation.